Catalytic conversion of 1, 2, 3, 4-tetrahydronaphthalene, indan, and other materials



United States Patent No Drawing. Filed Mar. 15, 1966, Ser. No. 534,42853 Claims. (Cl. 260-668) This application is a continuation-in-part ofmy prior application Ser. No. 388,693 filed Aug. 10, 1964, nowabandoned, the latter application being a continuation-inpart of myapplication Ser. No. 347,685, filed Feb. 27, 1964, now abandoned.

This invention relates in one aspect to a method of convertingpolycyclic aromatics containing a saturated ring such as1,2,3,4-tetrahydronaphthalene and indan to 1) polycyclic aromaticscontaining an additional saturated ring such as sym-octahydroanthracene(herein OHA), sym-octahydrophenanthrene (herein OHP), andas-hydrindacene, and (2) diaryl alkanes such as the followingphenyltetralylbutanes (hereinafter PTB) and the followingphenylindanylpropanes (hereinafter PIP).

wherein the bond of the substituent which intersects the bond joiningtwo ring carbon atoms means that the substituent is attached to eitherof those two ring carbon atoms. Both of the two isomers indicated byeach of the above formulae A and B are referred to herein as PTB and PIPrespectively. Where a specific isomer is meant it will be so indicated,thus 1 phenyl-4,6-tetralylbutane, 1-phenyl-4-S-tetralylbutane, l-phenyl3-5 indanylpropane, and l-phenyl-3-4-indanylpropane. The invention inanother aspect relates to a method of converting diaryl alkanes totricyclic aromatics; for example, PTB is converted to OHA and OHP andPIP is converted to ashydrindacene. In another aspect the inventionrelates to products such as the diaryl alkane l-(4-as-hydrindacene)-3-phenylpropane (herein HPP) as new compositions and to a method ofpreparing same. In a further aspect of the invention OHP and OHA areisomerized to OHA and OHP respectively.

The various products which can be made by the invention have a varietyof uses. For example, OHA and OHP can be converted to anthracene andphenanthrene respectively by passage over a selenium catalyst at about325 C. or to benzene tetracarboxylic acids by nitric acid oxidation, thelatter process being described in the copending application of W. D.Vanderwerif, Ser. No. 370,485 filed May 27, 1964. PTB, PIP, and HPP canall be converted to wetting agents by sulfonation and HPP is also usefulas an insecticide.

It is known that in the presence of MCI, 1,2,3,4-tetrahydronaphthalenedisproportionates to form a variety of products including OHA, OHP, andPTB. Thus,

EQUATION 1 AlCla A disadvantage of this method of making OHA, OHP, andPTB is that the yields of each product are low. For example the yield ofOHA and OHP in the above reaction is generally not over 15-30%. Anotherdisadvantage is that the reaction is not very selective for anyparticular product. For example, it is not possible in the AlClcatalyzed reaction of l,2,3,4-tetral1ydronaphthalene to make solely OHAand OHP or to make solely PTB. These and other disadvantages of theprior art are discussed in more detail hereinafter.

It has now been unexpectedly found that if the reaction depicted byEquation I is carried out in the presence. of HF-BF or HF-BCl improvedresults are obtained. One improvement is that the yield of OHA, OHP, andPTB is substantially higher. For example, by using HF- BF or HF-BCl ascatalyst OHA and OHP are obtained in almost theoretical yield, e.g.,Another improvement is that by proper control of the reactionconditions, particularly the reaction temperature, OHA and OHP can beobtained to the essentially complete exclusion of PTB, and PTB can beobtained to the essentially complete exclusion of OHA and OHP. In otherwords the reaction is highly selective when HF-BF or HF-BCl is thecatalyst. Additional improvements over the AlCl process are that thereaction is cleaner, i.e., less tars are formed, the reaction time isshorter, and the catalyst can be regenerated without loss of activity.

I have also found that in the presence of HF-BF or HF-BC13 indan isconverted in high yield and high selectivity to either as-hydrindaceneor PIP, the particular product obtained depending mainly upon thereaction temperature employed. I have also found in addition that in thepresence of HF-BF or HF-BCl PTB is converted to OHA and OHP and that PIPis converted to ashydrindacene. Additionally, in the presence of HF-BFor HF-BCI OHP can be isomerized to OHA and OHA can be isomerized to OHP.The other aspects of the invention mentioned previously are discussedmore fully hereinafter.

The aspect of the invention relating to the conversion of1,2,3,4-tetrahydronaphthalene to OHA and OHP or to PTB will be describedin detail first after which the other aspects of the invention will bedescribed in detail. In all the description it will be assumed, unlessotherwise indicated, that the catalyst is HFBF although unless otherwiseindicated HFBCi3 can also be used. The

3 theoretical reactions involved in the formation of OHA, OHP, and PTBare as follows:

1,2,3,4Tetrahy- HA dronaphthaieno 1,2,3,4-Tetrahy- 0 HP dronaphthalene1,2,3,4-Tetrahydrouapntlialeno According to the invention1,2,3,4-tetrahydronaphtha lene is converted to OHA and OHP or to PTB bycontacting the 1,2,3,4-tetrahydronaphthalene at certain temperatureswith certain amounts of HF and BF The following description of thereaction conditions and the method of carrying out the reaction isapplicable to the preparation of PTB as well as OHA and OHP unlessotherwise indicated. It should also be noted that the PTB produced bythe method of the invention is essentially the -6 isomer rather than theisomer. A small amount of the latter is present but it is usually notmore than about 1% or so. Subsequent examples refer to the PTB contentof the reaction product and the stated amount includes both isomersalthough as mentioned the amount of the -5 isomer is very small. Anyother reference to PTB in the following description of the inventionincludes both isomers.

The HF should be employed in liquid phase. Although the reaction can be,and preferably is, carried out above the boiling point of HF (19.4 C.)the pressure in the reaction vessel should be sufiicient to maintain theHP in liquid phase. All boiling points herein are at 760 mm. Hg absolutepressure unless otherwise stated. Normally the BF (B.P.=-l C.) pressurein the reaction vessel is suflicient to maintain the HP in liquid phase.If not other convenient means can be employed to insure the use ofliquid HF, such as pressuring the reaction vessel with nitrogen, etc.The amount of HF employed should be at least 5 moles per mole of1,2,3,4-tetrahydronaphthalene but is preferably at least 7 moles, morepreferably at least 10 moles, per mole of 1,2,3,4-tetrahydronaphthalene.The subsequent examples show that increasing theHF:1,2,3,4-tetrahydronaphthalene ratio increases the yield of OHA andOHP or the yield of PTB, i.e., the yield of product, at least up toHF:1,2,3,4-tetrahydronaphthalene mole ratios of about 10:1, and that thehigh yields which characterize my methods for preparing these productsare not obtained at HF:1,2,3,4-tetrahydronaphthalene ratios lower thanthose specified. Preferably the HF:1,2, 3,4-tetrahydronaphthalene moleratio does not exceed about 50:1, although ratios as high as 200:1 oreven higher can be used if desired.

The amount of BF used should be at least 0.5 mole per mole of1,2,3,4-tetrahydronaphthalene and is preferably at least 0.6 mole permole of l,2,3,4-tetrahydronaphthalene. Although some product is obtainedat BF yield as the ratio exceeds 0.5:1. More preferably the BF:1,2,3,4-tetrahydronaphthalene ratio is at least 0.75:1. The yield ofproduct is usually maximized at a BF 1,2, 3,4-tetrahydronaphthaleneratio in the range of 0.521 to 2.0: 1, consequently the amount of BFused will normally not exceed 2 moles per mole of1,2,3,4-tetrahydronaphthalene although amounts as high as 10 moles permole of 1,2,3,4-tetrahydronaphthalene or even higher, e.g., 100 molesper mole of 1,2,3,4-tetrahydronaphthalene can be used if desired. Thesubsequent examples show more clearly the effect of the BF:1,2,3,4-tetrahydronaphthalene ratio on the yield of product.

The temperature at which the reaction is carried out will, inconjunction with the reaction time, determine the product obtained andthe amount thereof. At temperatures in the range of 15130 C. OHA and OHPcan be formed in high yields and, in addition, they can be formed to theessentially complete exclusion of PTB. Preferably the reactiontemperature is 30-100 C. The subsequent examples show that the yield ofOHA and OHP is usually maximized at a temperature of 40-80 C., hencethis is the more preferred temperature range. PTB can be formed in highyields at temperatures in the range of 100 C. to 15 C. and, in addition,can be formed in this range to the essentially complete exclusion of OHAand OHP. Preferably the temperature is in the range of to 0 C., morepreferably 60 to 10 C. The subsequent examples show more clearly thedependency of the product obtained on the reaction temperature. Theinfluence of reaction time on the optimum reaction temperature isdiscussed subsequently.

The time for which the 1,2,3,4-tetrahydronaphthalene and HF-BF arecontacted can vary considerably. Whether the desired product is OHA-OHPor PTB, a substantial amount of reaction occurs almost immediately,i.e., within 1-2 minutes, with additional reaction occurring at a slowerrate thereafter until at about minutes (for a reaction temperature of 50C.) maximum yield of product is obtained. Where the desired product isOHA and OHP the amount of PTB formed, although extremely small in anycase, tends to decrease as the reaction time increases. Consequentlywhen OHA and OHP are being prepared the reaction time will normally beat least 5 minutes preferably at least 20 minutes, more preferably atleast 45 minutes. Normally the reaction time will not exceed 10 hours,usually it will not exceed 5 hours and in many cases reaction times lessthan 2 hours will be satisfactory. Where the desired product is PTB, theamount of OHA and OHP formed, although extremely small in any case,tends to increase as the reaction time increases. Consequently thereaction time preferably does not exceed 5 hours, more preferably itdoes not exceed 3 hours. In many cases reaction times less than 1 hourwill be satisfactory. The minimum reaction time employed will usually beat least 0.5 minute, more frequently 5 minutes and is preferably atleast 10 minutes. The subsequent examples show more clearly the effectof reaction time on yield of product.

In preparing either OHAOHP or PTB the reaction time and temperature areinterrelated in that as the time increases the temperature at whichmaximum yield of product is obtained decreases somewhat. Consequently itis impossible to specify any single optimum temperature or any singleoptimum time. This interrelation is shown more clearly in the subsequentexamples. Within the temperature and time ranges specified above,however, as the temperature increases or decreases the time required toeffect the same yield of product will decrease or increase,respectively. Stated in another manner the temperature is inverselyproportional to the time.

The reaction can be carried out in any convenient manner using equipmentof conventional type. For example, the 1,2,3,4-tetrahydronaphthalenestarting material is charged to a closed reaction vessel equipped withheating and agitation means. Where the reaction temperature is less thanthe melting point of 1,2,3,4-tetrahydronaphthalene, -30 C., the1,2,3,4-tetrahydronaphthalene starting material is preferably dissolvedin an inert solvent such as pentane, hexane, heptane, etc. The requiredamount of HF is then added following which the HF-1,2,3,4-tetrahydronaphthalene mixture is heated to the desired reactiontemperature. Next the desired amount of BF is added and the vessel isthen preferably shaken or the contents thereof otherwise agitated inorder to insure efiicient contact of the HF-BF catalyst with thel,2,3,4-tetrahydronaphthalene. After adding the BF the reaction mass isthen maintained at the reaction temperature for the desired contacttime. The BF is purposely added after the reaction temperature isreached because no reaction occurs until the BF is added. Since theproducts obtained depend upon the reaction temperature it is generallydesirable that no reaction occur until the desired temperature isreached.

At the end of the reaction period the reaction vessel contains HF, BFeither OHA and OHP or PTB, some unreacted 1,2,3,4-tetrahydronaphthalene,benzene when the product is OHA and OHP, and an almost negligible amountof other by-products. Merely opening the vessel Will afiect the removalof most of the BF (B.P.=101 C.) and much of the HF if the reaction iscarried out above its boiling point (19.4 C.). Any remaining HF and anyBF dissolved therein can be distilled from the vessel. The OHA and OHPor the PTB as the case may be can be separated from the other organicmaterials by means described hereinafter.

If it is desired to remove the HF as a liquid rather than as a gas thereaction vessel is cooled to below 19.4 C. at the end of the reactiontime, assuming that the reaction is carried out above the boiling pointof HP. The vessel is then opened, which effects removal of most of theBF and the remaining reaction mass is quenched in ice water. T-wo liquidlayers result, an aqueous acid layer and an organic layer. If desired,the acid in this two-phase system can be neutralized by mixing thesystem with Na CO The organic layer is then decanted and is preferablywashed with water several times to remove any remaining traces of acidor any traces of Na CO Dilution of the organic layer with a solvent suchas pentane facilitates the decanting step.

Where the desired product is OHA and OHP, they can be recovered from theorganic layer in any convenient manner. One suitable procedure involvesan initial vacuum distillation at, for example, 0.1 mm. Hg pressure. Allpressures herein are absolute pressures. The byproduct benzene (B.P. 83C.) distills first followed by the unreacted1,2,3,4-tetrahydronaphthalene (B.P.= 206 C.). These distillates can berecovered together or separately and put to any use desired. Forexample, unreacted 1,2,3,4-tetrahydronaphthalene can be recoveredseparately and recycled to the reaction vessel and again contacted WithHF-BF for conversion to OHA and OHP. The OHA and OHP distill off next,sometimes with a very small amount of impurities. Distillation of theOHA and OHP sometimes leaves an almost negligible residue of highboiling -by-products. OHA and OHP boil at about 292 and 295 C. at 760mm. Hg respectively according to the few literature references althoughI have found, using an efficient distillation column, that they boil atabout 306.5 C. and 311.7 C. at 760 mm. Hg. In any event at 0.1 mm. Hgthey distill off at about 8085 C. If the distillation apparatus issufficiently eflicient the OHA and OHP can be distilled off andrecovered separately. Usually, however, it is more convenient to distilland condense them together and recover a mixture of OHA and OHPcontaining, usually, a small amount of impurities. In most cases thetemperature of this mixture will be above 74 C., in which caserelatively pure OHA can be recovered therefrom by cooling the mixtureto, say, room temperature and then separating the resulting crystallizedOHA by, for example, filtration. The separated OHA, which is relativelypure OHA because its purity is substantially higher than the OHA contentof the original mixture, can be further purified by recrystallizationfrom an alcohol such as methanol at room temperature. The filtrate is aliquid mixture of OHP and a relatively small amount of OHA. It can bedescribed as relatively pure OHP because the OHP content of the filtrateis substantially higher than the OHP content of the original mixture. Ifthe OHA-OHP distillate fraction is condensed at, say, room temperaturethe condensate is a slurry of solid, relatively pure OHA, in a liquidmixture which is relatively pure OHP. In this case the relatively pureOHA can be separated immediately; there is no need to cool the mixture.A more detailed explanation for the methods just described forseparating OHA and OHP from an OHA-OHP mixture is as follows: OHA andOHP melt at 74 C. and 16.7 C. respectively and above 74 C. an OHA-OHPmixture is a homogeneous liquid. If such a mixture is cooled attemperature is reached at which solid material crystal-- lizes. Thissolid material is relatively pure OHA. The exact temperature at whichsolid material (relatively pure OHA) begins to crystallize will varydepending upon the ratio of OHA to OHP in the original mixture. In allcases, however, the temperature at which solid material crystallizesfrom the mixture will be lower than 74 C. In my process the ratio of OHAto OHP in the reaction product is usually about 1.3-1.4 to 1. In suchcases a temperature of 20 C. is sufiicient to effect crystallization ofa substantial amount of relatively pure OHA; hence the original mixtureis preferably cooled to at least 20 C. More preferably the originalmixture is cooled to at least 10 C.

Once a temperature is reached at which relatively pure OHA hascrystallized, further reductions in temperature result incrystallization of additional OHA. As the amount of crystallized OHAincreases, the amount of OHA in the remaining liquid decreases or,conversely, the OHP content of the remaining liquid increases. Theslurry of solid in liquid should not, obviously, be cooled to atemperature low enough to cause solidification of the entire slurry,i.e., the slurry should not be cooled below the freezing point of theoriginal OHA-OHP mixture. The freezing point of OHA-OHP mixtures willvary depending upon the relative amount of each ingredient in themixture. In most cases, however, the slurry can be cooled to about 5 C.without complete solidification thereof. In order to minimize OHPcrystallization, the mixture is preferably not cooled below 2 C.

The separation of OHA from OHP is described in more detail in thecopending application of W. D. Vanderwerff Ser. No. 347,671 filed Feb.27, 1964. In this connection the phase diagram of the OHA-OHP systemshown in the copending application of I. N. Duling, Ser. No. 434,541filed Feb. 23, 1965 is useful.

The separated OHA can if desired be isomerized to OHP by means of HF andBF or, conversely, the OHP remaining after separation of the OHA can ifdesired be isomerized to OHA. These isomerizations are described indetail subsequently.

Where the desired product is PTB it can be recovered from the organiclayer by, for example, distillation at reduceed pressure. At 15 mm. HgPTB distills off at about 230245 C. and at 0.3 mm. Hg it distills off atabout 1'75190 C. If desired the PTB can be separated by other convenientmethods such as chromatographic techniques.

The following examples illustrate the preparation of OHA, OHP, and PTBaccording to the invention and, in addition, the effect of the variousreaction conditions discussed previously upon the yield of product. Theprocedure in each run is essentially the same and is as follows:

The reaction vessel is a small react-or equipped with either an externalshaker or an internal agitator and also equipped with heating andcooling means. The reactor is flushed out with nitrogen and is thenevacuated. l,2,3,4- tetrahydronaphthalene is then charged to the reactorfollowed by the HF. The amount of 1,2,3,4-tetrahydronaphthalene chargedis 0.1 mole and is the same in all runs. The reactor is shaken, heatedto the desired reaction temperature, and the BE, is then added. In allruns the BE, pressure is sufiicient to maintain essentially all of theHP in liquid phase. The reactor is then held at the reaction temperaturefor the desired reaction time, the time being measured from the time ofBF addition. Shaking of the reactor continues throughout the entirereaction time. At the end of the reaction period the reactor is cooledto C., opened, and the contents thereof quenched in ice. Two liquidlayers result, an aqueous acid layer and an organic layer. Thistwo-phase system is neutralized with Na C-O after which the organiclayer is drawn off and washed several times with twice its volume ofWater. The organic layer is then analyzed by vapor phase chromatography.In Run 411215 only the organic layer remaining after using a smallamount thereof for the chromatographic analysis is treated as follows inorder to isolate OHA and OHP therefrom. The organic layer is charged toa distillation column equipped with a condenser and is distilled at apressure of 0.1 mm. Hg. Benzene and 1,2,3,4-tetrahydronaphthalenedistill first and are discarded. The material distilling between 80 and85 C. is condensed at room temperature and collected. The condensate isa slurry of solid in liquid. The solid is separated by filtration and isdissolved in methanol at 50 C. using 15 mls. methanol per gram of solid.The methanol solution is cooled to C. and the resulting crystallizedsolid separated by filtration. This solid analyzes 99.5% OHA.

In Run 429180 only the organic layer remaining after using a smallamount thereof for the chromatographic analysis is distilled at 0.3 mm.Hg. The material distilling between 175 and 190 C. is collected and isfound upon analysis to be essentially pure PTB.

Example I This example is a series of runs at a constant HF:1,2,3,4-tetrahydronaphthalene mole ratio of 10:1, a constant reactiontime of 90 minutes, a constant temperature of 50 C., and at varying BF:1,2,3,4-tetrahydronaphthalene mole ratios. The data in Table I belowshow the BF :1,2,3,4-tetrahydronaphthalene mole ratio, the 1,2,3,4-tetrahydronaphthalene conversion, i.e., the weight percentage of the1,2,3,4-tetrahydronaphthalene starting material which reacted to formproducts of any type, the total yield of OHA and OHP and the yield ofPTB. The yield is by weight based on the total weight of 1,2,3,4-tetrahydronaphthalene starting material, not on the weight of reacted1,2,3,4-tetrahydronaphthalene, and is calculated according to thetheoretical reactions presented previously.

TABLE I 'lemp.=50 C. Time=90 min. HF: 1,2,3,4-tetrahydronaphthalenerati0=10z1 It is evident from the data contained in Table I that at BF:1,2,3,4-tetrahydronaphthalene ratios above 0.5 :1 extremely high yieldsof OHA and OHP are obtained while the yields of PTB are negligible. Itis also evident that for BF :1,2,3,4-tetrahydronaphthalene ratios below0.5:1 the yields of OHA and OHP are relatively low. It should be clearlynoted that the stated yields in Table I are based on the total weight ofstarting material. By dividing the stated yields by the fraction of1,2,3,4-tetrahydronaphthalene, converted it will be apparent that for BF:1,2,3,4-tetrahydronaphthalene ratios above 0.5:1 over of the1,2,3,4-tetrahydronaphthalene which reacts forms OHA and OHP.

Example 11 This example is another series of runs showing the effect ofthe BF :1,2,3,4-tetrahydronaphthalene ratio on product yield. The onlydifference between this example and the previous example is that allruns in Example II are at 70 C. rather than 50 C. The reaction time andHF:1,2,3,4-tetrahydronaphthalene mole ratio are the same as in ExampleI. The results of the runs are summarized in Table II below.

TABLE II Temp.=70 O.

Time=90 min.

HF; 1,2,3,4-tetrahydronaphthalene ratio=10z1 Moles BF 1,2,3.4-tetra-Yield, Percent Mole 1,2,3,4- hydronaph- Run No. tetrahydrothalenenaphthalene Conversion, OHA-OHP PTB Percent The data contained in TableII also show that there is a distinct increase in the yield of OHA andOHP as the BF :1,2,3,4-tetrahydronaphthalene ratio exceeds 0.521. Thedata also show that for BF :1,2,3,4-tetrahydronaphthalene ratios above0.5 :1 and other reaction conditions as stated no PTB is formed.Preferably the BF :1,2,3,4tetrahydronaphthalene ratio is at least 0.611,more preferably at least 0.75:1.

Example III This example is another series of runs showing the effect ofthe BF :1,2,3,4-tetrahydr0naphthalene ratio on product yield. The onlydifference between this example and Example I is that all runs inExample III are at 30 C. rather than 50 C. The reaction time and HF:1,2,- 3,4-tetrahydronaphthalene mole ratio are the same as in Example I.The results of the runs are summarized in Table III below.

TABLE III Temp.=30 C. Time=90 min. HF: 1,2,3,4-tetrahydronaphthaleneratio=10z1 Moles BFJI 1,2,3.4-tetra- Yield, percent Mole 1,2,3,4-hydranaph- Run No. tetrahydrothalene naphthalene Conversion, OHA-OHP PTBpercent The data contained in Table III also show that there is adistinct increase in the yield of OHA-OHP as the 1 Example V] Thisexample is another series of runs showing the effect of reaction time on.product and yield thereof. In each Example IV run the HF:1,2,3,4-tetrahydronaphthalene mole ratio is This example is Six runsShowing the effect of tha :1, the reaction temperature is 50 C and theB1 HF:1,23,4 tetrahydronaphtha1ene ratio on the yield of1,2,3,4-tetrahydronaphthalene mole rat10 1s 0.60:1-0 .65:l. product Thereaction time and temperature are 90 Essentially the only differencebetween the runs of Examutes and C respectively in all runs TheBF3;1,2,34 ples V and VI 1s that rrnxrng of the reactor ingredients istetrahydronaphthalene mole ratio is essentially the same 10 an eXtel'nalShaker 111 Example V and y an Internal i h run, varying between 61 d 07;1 From h agitator in Example VI. It is believed that the lattermixdata in Table I it is apparent that at this BF :l,2,3,4-tetras deviceis superior hence the better yields and faster hydronaphthalene levelthis slight difference in the amount reaction in Example VI. The resultsof the runs of Examof BP will not cause any significant change inproduct ple VI are shown in Table VIbeloW. yield. The results of ExampleIV are tabulated in Table IV below.

. TABLE VI i iff t h dr hthl t o :,,,-eray ona aene a'i=l :1 T 50 0TABLE Iv BFa:1,2,3,4-tetrahydrona phthaleneiatib=O.6:l0.65:1

em Tim=90 min. BF :1,2,3,4-tetrahydronaphtha1ene rati0=0.6:10.7:11,2,3,4tetra- Yield, percent;

Reaction hydronaph- Run No. Time in thalene HF:1,2,3,4- 1,2,3,4-tetra-Yield, percent Minutes Conversion, tetrahydrohydronaphpercent OHA-OHPPTB Run No. naphthalene thalene Mole Ratio Conversion,

percent OHA-0H1 PTB 429160 10 83. O 58. 8 11. 0 429163 85.6 31. 0 3.6429164 60 89.3 84.9 1.1 1:1 41. 5 37. 6 3 429161 120 95. 5 91. 0 0 5:176. 2 65. 0 1. 5 429162 180 96. 6 93. 8 0 9.31 93.9 87.2 0 30 429165.300 95.2 91.7 0 10.711 86.0 81.0 0 14.3:1 91.0 34.7 0 20:1 90.2 89.7 0

The data contained in Table VI confirm the conclusions drawn with resect to the data contained in Table V. It 1s evident from the datacontamed 1n Table IV that p high yields of OHA-OHP are not obtaineduntil the Example VII HF:1,2,3,4-tetrahydronaphthalene ratio reachesabout 5 1. 1 h h h As stated previously the amount of HF employed should40 S examp,e er Sales S owmg t e be at least 5 moms Preferably at least7 moles, more effect of react1on time on product and y1eld thereof. Inpreferably at least 10 moles, per mole of 1,2,3,4 tetra each run theHF:1,2,3,4-tetrahydr0naphthalene rat10 1s hydrmmphth316116- 10:1, thetemperature is 0 C., and the BF :1,2,3,4-tetrahydrona-phthalene ratio isabout 1.1:1. The results of Example V these runs are shown in Table VIIbelow. This example is a series of runs showing the effect of reactiontime on product and yield thereof. In each run theHF:1,2,3,4-tetrahydronaphthalene mole ratio is 10:1, TABLE VII thereaction temperature is C., and the BF :1,2,3,4- I{%mp.2-0;tCt. h at hthl 10 1 :1,,,- ona eea1=: tetrahydronaphthalene mole ratio is O.6.1-0.65.1. The 50 i g i fi i fi results of these runs are shown m Table Vbelow.

1,2,3,4-tetra- Yield, percent; Reaction hydronaph- Run No. Time inthalene TABLE V Minutes Conversion, OHA OHP PTB Temp.=50 C. percentHF:1,2,3,4-tetrahydronaphthalene ratio=10z1 BF:1,2,3,4-tei2rahydl0naphtha1ene rat1o=0.6:10.65 :1 5 40, 6 0 32, 0 1562.2 2.0 55.9

1,2,3,4-tetra Yield, percent Reaction y p 120 69.9 16.4 50.6 Run No. lge C thaw/11,9 180 67.9 22.9 41.4

r 1 mu es (15 5 11 OHA OHP PTB 300 76.8 29.8 40.2

15 60.1 55.5 6.2 30 69.0 64.9 3.7 45 76.4 69.6 2.0 6g 3%; i6 The datacontained in Table VII also show that longer 3 1 reaction times favorthe formation of OHA and UHF and 93 300 that once the maximum amount ofPTB is formed additional reaction time results in a reduction in PTByield. The results of Tables V, VI, and VII are discussed againsubsequently.

Example VIII This example is several runs showing the eifect of reactiontemperature on product and yield thereof. In each run theHF:1,2,3,4-tetrahydronaphthalene mole ratio is 10:1 and the reactiontime is 90 minutes. In the C. and the 10 C. runs the B1:1,2,3,4-tetrahydronaphthalene ratio is 1.1:1-1.2:1 and in the otherruns shown is 0.6:1-0.7:1. The results of these runs are summarized 5 inTable VIII below.

TABLE VIII Time=ll0 min. HF :l,2,3,4-tetral1ydronaphthalene ratio 1 BF:1,2,3,4-tetrahydronaphthalene ratio=0.6:l-1.2:1

1,2,3,4-tetra- Yield, Percent Reaction hydronaph- Run No. Te1nperathalene ture, 0. Conversion, OHAOHP PTB Percent It is apparent from thedata contained in Table VIII that low temperatures favor the formationof PTB whereas high temperatures favor the formation of OHAOHP.

Example IX This example is another series of runs showing the effect ofreaction temperature on product and yield thereof. In each run theHF:1,2,3,4-tetrahydronaphthalene mole ratio is 10:1, the B1:1,2,3,4-tetrahydronaphthalene mole ratio is 0.6:1-0.65 :1 except in therun at 0 C. in which the ratio is 11:1, and the reaction time is 30minutes. As in prior examples this difference in the BF ratios will notchange the yield of product significantly. Thus the difference betweenthis example and Example VIII is in the reaction time. The results ofExample IX are summarized in Table IX below.

temperatures favor the formation of OHA and OHP whereas lowertemperatures favor the formation of PTB. Examples V-IX collectively shownot only the eifect of reaction time alone and reaction temperaturealone but also the interrelation of these two variables. For example ata reaction time of 90 minutes the OHAOHP yield is maximized at atemperature of about 50 'C. under the experimental conditions describedwhereas the optimum temperature for a reaction time of 30 minutes isabout C. This is clearly demonstrated by plotting the data contained inTables VIII and IX. Consequently, as was pointed out previously nosingle time or temperature can be specified as being optimum. As alreadystated the temperature for OHAOHP preparation should be 15130 C.,preferably 30100 C., more preferably 4080 C., and that for PTBpreparation should be -100 to 15 0., preferably to 0 C., more preferably60 to 10 C. For OHAOHP preparation the reaction time should usually be 5minutes-10 hours, preferably 20 minutes-5 hours, more preferably 45minutes-2 hours and for PTB preparation should usually be 0.5 minutes- 5hours, preferably 5 minutes3 hours, more preferably 1060 minutes. Withinthese ranges it is apparent from the above examples not only that highyields of either product can be achieved but also that either productcan be made to the essentially complete exclusion of the other. Thus thedata show that OHAOHP yields of 65-75% and even 80-90% are readilyobtainable. In addition, in preparing OHAOHP the amount of PTB formedcan be maintained below 10% or even 5% or 2% without difficulty.Similarly the amount of OHA- OHP formed in preparing PTB can bemaintained below 10% or even 5% without difiiculty.

It was mentioned previously that BC1 can be used in place of BF This isdemonstrated by a run (454914) the same as run 411196 reportedpreviously (Table I) except that BC1 is used instead of BF In the BC1run the 1,2,3,4-tetrahydronaphthalene conversion is 85.2%, the OHAOHPyield is 70.6%, and the amount of PTB is undetermined. Although theseresults are not quite as good as those obtained with BB, they do showthat the HFBCl catalyst is highly effective. To eliminate thepossibility that in the BCl run some of the BCI;; was converted byreaction with HF to BF two runs, 454946 and 454947, were made in whichthe reactor was pressured with 50 and p.s.i.g. HCl respectively. TheOHAOHP yield in both of these runs is substantially the same and is alsosubstantially the same as the BCl run in which the reactor was notpressured with HCl.

According to another aspect of the invention indan is converted toas-hydrindacene or PIP by contacting the indan with HF and BE, or BC1under certain conditions, the conditions employed determining theproduct obtained. The theoretical reactions involved in this aspect ofthe invention are as follows:

indan as-hydrindacene indan I I P This aspect of the invention isdescribed in more detail as follows, in which description it will againbe assumed that the catalyst is HF-BFg.

It was pointed out in the discussion of the preparation of PTB that thePTB produced is essentially the 6-isompr rather than the 5-isomer, theamount of the latter being almost negligible. When the starting materialis indan the PIP produced contains both isomers, i.e., the 4 and 5isomers. The 4 isomer predominates but the amount of the 5 isomer issignificant, the ratio of the 4 isomer to 5 isomer generally being about1.8 to 1. Subsequent examples refer to the PIP content of the reactionproduct 13 and the stated amount includes both isomers. Any otherreference to PIP in the following description of the invention includesboth isomers.

In preparing either as-hydrindacene or PIP the amounts of HF and BFshould be as described previously for the HF-BF catalyzed conversion of1,2,3,4-tetnahydro naphthalene. Thus the molar ratio of HF to indanshould be at least 5: 1, preferably at least 7:1, more preferably :atleast 10:1. The HF should also be employed in liquid phase. The BFzindan mole ratio should be at least 0.5:1, preferably at least 0.6: 1,more preferably at least 0.75:1. As in the case of thel,2,3,4-tetrahydronaphthalene reaction there is a rapid increase inyield of product as the BF zindan mole ratio exceeds 0.5 :1.

The reaction temperature employed will determine the product obtained.At relatively low temperatures high yields of PIP are obtained to thesubstantial exclusion of as-hydrindacene. As the temperature increasesthe yield of PIP decreases and the yield of as-hydrindacene increasesuntil finally at relatively high temperatures high yield s ofas-hydrindacene are obtained to the substantial exclusion of PIP. Inpreparing as-hydrindacene the temperature should be in the range of40l20 C., preferably 50l00 C. The more preferred temperature range is5585 C. In preparing PIP the reaction temperature should be; 20 to 80C., preferably 60 C., more preferably 1545 C. The effect of reactiontemperature upon the type of product and yield thereof is shown moreclearly in the subsequent examples.

The reaction time, i.e., the time of contact of the HF- BF and the indancan vary considerably. In preparing either product a substantial amountof reaction occurs within 1-2 minutes with additional reaction occurringthereafter at a slower rate. In preparing as-hydlrindacene the reactiontime is usually at least 2 minutes, preferably at least 10 minutes, morepreferably at least 30 minutes. In most cases the reaction time will notexceed 10 hours, usually it will not exceed hours and in many casestimes less than 3 hours will be satisfactory. In preparing PIP thereaction time will usually be not more than 3 hours, preferably not morethan 1 hour, more preferably not more than 30 minutes. The minimumreaction time will usually be 0.5 minute, more frequently 2 minutes, andpreferably is at least 5 minutes. Often the reaction time will be atleast 30 minutes.

With respect to product and yield thereof the reaction time andtemperature are interrelated in the same manner as described inconjunction with the preparation of PTB and OHA-OHP. The subsequentexamples bring this out more clearly.

The conversion of indan to as-hydrinda-cene or PIP can be carried out inessentially the same manner as described hereinbefore for the covnersionof 1,2,3,4-tetrahydronaphthalene to OHA and OHP or PTB, the onlysignificant differences being in the starting material (which is indaninstead of 1,2,3,4-tetrahydronaphthalene) and in the recovery of productfrom the organic phase resulting from either the quenching of thereaction product mixture inwater or the distillation of the catalystfrom the reaction product mixture. Where the product is as-hydrindaceneit can be recovered from the organic layer by, say, elutionchromatography or by vacuum distillation. as-Hydrindacene distills fromthe organic layer at about 110-125 C. at 9 mm. Hg pressure. PIP can alsobe recovered from the organic layer by chromatographic techniques or byvacuum distillation. PIP distills from the organic layer at about l50l55C. at 0.7 mm. Hg or at about l95200 C. at 13 mm. Hg.

The following examples illustrate the preparation of PIP andas-hydrindacene according to the invention.

Example X This example is a series of runs all of which are conducted inessentially the same manner described previously for Examples LIX, themain differences being that 0.1 mole of indan is used instead of 0.1mole of 1,2,3,4-tetrahydronaphthalene and, separating and recovery ofproduct from the organic layer is by gas chromatography. Thechromatographic column contains as adsorbent Chromosorb W (JohnsManville Corporation) having deposited thereon 15% silicone gum rubber(SE54, Analytical Engineering Laboratories, Inc., Hamden, Connecticut).The column is programmed from 320 C. to facilitate separation ofreaction products. The products are eluted from the column with helium.In each run the HFtindan mole ratio is 10:1 and the reaction time is 90minutes. The other reaction conditions are shown in Table X below alongwith the yield of as-hydrindacene and PIP in each run. The yields arebased on the total weight of starting material.

TABLE X Time-90 min. HF: indan ratio= 10:1

Yield, percent Moles BF Reaction Indan Con- Run No. Mole Temp., version,

Indan 0. percent as-Hy- PIP drindaeene The data contained in Table Xclearly show the criticality of the reaction temperature in determiningthe type of product formed. The optimum temperature at a 90 minutereaction time is about 70 C. for as-hydrindacene formation and is about30 C. for the preparation of PIP. The data also show that high yields ofproduct are obtained. For example, by dividing the stated yield of PIPat 30 C. by the fraction of indan converted it can be determined thatabout 90% of the indan which reacts to form any products forms PIP.

Example XI This example is a run which is the same as Run 429253 aboveexcept that the BF :indan ratio is 0.11:1 instead of 0.61:1. The resultsof this run are shown in Table XI below, along with the results of Run429253.

I It is apparent from the data contained in Table XI that a BF :indanmole ratio of 0.11:1 results in essentially no reaction at all. For thepresent purpose the BFgIll'ldfiD.

15 ratio should be at least 0.5:1, preferably at least 0.6:1, morepreferably at least 0.75: 1.

Example XII This example is a series of runs similar to those of ExampleX but showing the variation in product and yield thereof with reactiontime. In each run the BF :indan ratio is 0.921 to 1.1:1, the HF:inda-nratio is 10:1 and the reaction temperature is 70 C.

TABLE XII Temp.=70 C. BF;:indan ratio=0.9:l1.1:l HF :indan ratio 10:1

The results of Example XII show that longer reaction times favor theformation of as-hydrindacene whereas shorter reaction times favor theformation of PIP. When considered with Example X, Example XII shows theinterdependency of reaction time and temperature. For example, at 70 C.a minute reaction time results in a 64% yield of PIP where as at 30 C.about the same yield is obtained at a 90 minute reaction time.

From the data contained in Tables X-XII it is apparent that theconversion of indan to as-hydrindacene or PIP is very selective and thathigh yields of either product can be obtained. Thus PIPzas-hydrindaceneratios of 4:1 or even as high as :1 or 20:1 can be achieved. Similarlyas-hydrindacenezPIP ratios of 421-5 :1 can be obtained. Yields of 45-55%for either product are readily obtainable.

The invention has so far been described with respect to thedisproportionation of tetralin and indan. As described hereinbef-ore theinvention is applicable to other polycyclic aromatics having certainstructural properties characteristic of 1,2,3,4-tetnahydronaphthaleneand indan and they can be described as follows: they are described aspolycyclic because they have more than one ring and they are describedas aromatic because they contain at least one aromatic ring. In additionthey contain a condensed ring group, i.e., a plurality of rings each ofwhich is condensed either directly or through other rings to every otherring in the group. The group is itself characterized in that it containsan unsubstituted aromatic ring having exactly two condensed carbon atomsand an unsubstituted saturated ring having exactly two condensed carbonatoms. For example, in 1,2,3,4-tetrahydronaphthalene the aromatic ringcontains four unsubstituted carbon atoms and exactly two condensedcarbon atoms; likewise for the saturated ring. Typical examples of thesestarting materials are 1,2,3,4 tetrahydronaphthalene, indan,1,2,3,4-tetrahydroanthracene, 1,2,3,4,-tetrahydrophenanthrene,1,2,3,4,9,10 hexahydroanthracene and benz[f]indan, the nomenclature ofthe latter compound being according to the Ring Index. In most cases thestarting material will contain less than about 34 rings usually having5-6 carbon atoms per ring.

The products produced are, as already described, of

two types. One type is the same as the starting material 16 except thatthe originally unsubstituted aromatic ring having exactly two condensedcarbon atoms has an unsubstituted saturated ring condensed therewith.The other type is a diaryl alkane which results from the originallyunsubstituted saturated ring opening up at one of its condensed carbonatoms and the terminal carbon atom of the resulting chain of carbonatoms attaching to a carbon atom of an unsubstituted aromatic ringhaving exactly two condensed carbon atoms of another molecule ofstarting material.

That other starting materials such as those described above are suitablefor the present purpose is shown by an experiment in which1,2,3,4-tetrahydroanthracene is contacted with 8.2 moles HF and 0.97mole BF each being per mole of starting material, at a temperature of 50C. for minutes. The reaction is conducted in the same manner as the1,2,3,4-tetrahydronaphthalene runs described hereinbefore. Analysis ofthe reaction product mixture showed the presence of1,2,3,4,8,9,10,1l-octahydrobenz[a] anthracene (Ring Index).

The reactions involved in the methods of the invention so far describedinvolve the reaction of a quantity of starting material with anotherquantity of starting material. For this reason the reactions arereferred to selfreactions.

In Run 429148 above (Table X) the chromatographic separation techniqueemployed also yields 1-(4-as-hydrindacene)-3-phenylpropane (HPP) as aproduct of the reaction. The numbering of the as-hydrindacene sub-.stituent is according to the Ring Index. As mentioned before one aspectof the invention is HPP as a new composition and a method of preparingsame. This compound has the following structure:

-o-o-o The yield of HPP in Run 429148 is 15.2% based on the followingtheoretical reaction:

The structure of the HPP obtained in Run 429148 is shown by thefollowing analytical results. By mass spectographic analysis it has amass of 277 versus the theoretical 276. Its infrared spectrum showsabsorption bands at 700, 750, 1740, 1790, 1860, and 1930 cmf which showsthe presence of a mono-substituted benzene. The spectrum also showsabsorption bands at 1740 and 1860 cm.- which shows a penta-substitutedbenzene. Finally the spectrum shows an absorption band at 870 cm.- whichis due to the aromatic hydrogen on the as hydrindacene radical. Nuclearmagnetic resonance analysis shows 25.2% aromatic hydrogens, 49.9% alphahydrogens, i.e., non-aromatic hydrogens attached to carbon atoms alphato a benzene ring, and 24.9% beta hydrogens. This compares to thetheoretical values of 25%, 50%, and 25% respectively.

The method of the invention for forming HPP involves contacting indanwith liquid HF and BF or BCl at a temperature in the range of 20 to 150C., preferably 40 to 120 C., more preferably 60 to 100 C. the amount ofHF should be at least 5 moles, preferably at least 7 moles, morepreferably at least 10 moles, per mole of indan. The amount of BF shouldbe at least 0.5, preferably 0.6, more preferably 0.75 mole per mole ofindan. In other words, the amount of HF and BF should be the same as inthe case of the, indan conversion described previously. The reactiontime is not critical but will usually be between 1 minute and 10 hours,preferably between 5 minutes and 5 hours, more preferably 30 minutes to3 hours. The reaction can be carried out in, for example, the mannerdescribed in conjunction with Run 429148.

Example XIII This example is a series of runs showing the preparation ofHPP. Each run is conducted in the same manner as Run 429148 supra withva BF zindan ratio of 0.6:1 to 1.17:1, an HFzindan ratio of 10:1 and areaction time of 90 minutes. The results are as shown in Table XIIIbelow.

Example XIV The runs of Example XII supra are set forth in Table XIVbelow but now showing the yield of HPP in each run.

TABLE XIV Run No Reaction Time, Yield of HPP,

Min. percent s 5. 5 1o 7. o 8.1 30 9. 5 60 10.8 90 7. o

The data contained in Table XIV show that long reaction tirnes are notnecessary to achieve significant yields f product.

According to another aspect of the invention PTB is converted to OHA andOHP and PIP is converted to as-hydrindacene by contacting the PTB or PIPwith HF and BF or BCl under certain reaction conditions. The theoreticalreactions involved are as follows:

C-C-C-C C-C-G l P IP as-Hydrindacone It should be noted that, asindicated in the above equations, regardless of which isomer of PTB orwhich isomer of PIP is used as the starting material the products arethe same. In other words either PTB isomer yields OHA- OHP and eitherPIP isomer yields as-hydrindacene. It is not known Whether, in the caseof PIP for example, the S-isomer preliminarily isomerizes to the4-isomer which is then converted to as-hydrindacene or whether the5-isomer is converted directly to as-hydrindacene. In any event,irrespective of the route in either of the above reactions, the productsare as indicated.

Whether the starting material is PTB or PIP the amount of HF used shouldbe at least 1 mole per mole of starting material. Preferably theHF:starting material mole ratio is at least 5:1, more preferably atleast 8:1. The HF should be employed in liquid phase. The molar ratio ofBF to starting material should be at least 0.1:1, preferably at least0.511, more preferably at least 0.75:1. The maximum amounts of HF and BFare not critical but will usually be as described for the conversion of1,2,3,4-tetrahydronaphthalene to OHA-OHP.

The reaction time can vary considerably. Regardless of whether thestarting material is PTB or PIP a substantial amount of reaction occurswithin 12 minutes followed by additional reaction at a slower rate.Preferably the reaction time is at least 30 minutes, more preferably atleast 60 minutes. The reaction time is preferably not more than 5 hours,more preferably not more than 3 hours.

The reaction temperature depends upon the particular starting material.In the case of PT B the reaction temperature should be in the range of=15 to 130 C., preferably 30 to C., more preferably 4080 C. In the caseof PIP -the reaction temperature should be in the range of 40 to C.,preferably 50 to 100 C., more preferably 55-85 C.

The conversion of PTB to OHA and OHP and the conversion of PIP toas-hydrindacene can be carried out in essentially the same manner asdescribed previously for the conversion of 1,2,3,4-tetrahydronaphthaleneto OHA and OHP, the only differences being the specific 19 startingmaterial employed. The products, OHA-OHP or as-hydrindacene, can berecovered from the reaction product mixture by, say, elutionchromatography or vacuum distillation.

The following example illustrates more specifically the aspect of theinvention now being discussed.

Example XV This example is a series of runs carried out in the samemanner as the runs shown in Table X supra except that 0.1 mole of PTB isused instead of 0.1 mole of indan, the PTB is dissolved in 50 mls. ofheptane, and except for the reaction conditions which are as stated inTable XV below along with the total yield of OHA and OHP, the yieldbeing based on the total weight of starting material. The conversion ofPTB in each run is essentially 100%. The PTB is obtained by the HFBFcatalyzed conversion of 1,2,3,4-tetrahydronaphthalene as describedhereinbefore.

It is evident from the data contained in Table XV that PTB can beconverted to OHA and OHP in high yield by the use of HFBF When thestarting material is PIP high yields of as-hydrindacene are obtained. Asmall amount of l,2,3,4-tetrahydronaphthalene is formed in each of theabove runs but as is evident from the yield data the major product isOHAOHP.

In a further aspect the invention embodies the isomerization of OHP toOHA and the isomerization of OHA to OHP both by means of HF and BF orBCl This embodiment is useful particularly in conjunction with thel,2,3,4-tetrahydronaphthalene disproportionation process describedpreviously. If for example OHA is the desired product in thedisproportionation process the OHP which is inevitably obtained in thatprocess can be isomerized to OHA. Similarly if OHP is the desiredproduct the OHA can be isomerized to OHP. Indeed, it is possible tocarry out the isomerization in the same reactor used for thedisproportionation. For example, at the end of the disproportionationthe temperature and the amounts of HF and BB, are adjusted to thosewhich are optimum for the particular isomerization desired and theisomerization is then allowed to take place.

The isomerization is carried out in a manner similar to that describedpreviously for the 1,2,3,4-tetrahydronaphthalene disproportionationprocess with the exception of course that the starting material is OHAor OHP rather than 1,2,3,4-tetrahydronaphthalene. In isomerizing OHP toOHA the BF :OHP mole ratio should be at least .05 :1. At a ratio of lessthan .05 :1 essentially no isomerization takes place and above a ratioof about 1:1 the mount of OHP which isomerizes drops off very sharply.Preferably the ratio is 0.221 to 0.8:1, more preferably about 0.6: 1.The HF:OHP mole ratio should be between 01:1 and 2:1, preferably 0.25:1to 1.5:1, more preferably 0.4:1 to 1.2:1. The isomerization temperatureshould be in the range of 30 to 60 C., preferably -50 C., morepreferably about 15 to about 30 C. The reaction, i.e., isomerization,time should be at least about 5 minutes and is preferably at least about20 minutes, more preferably at least 30 minutes. The

isomerization proceeds quite rapidly initially after which the ratethereof decreases. Normally the isomerization 5 time-will not be morethan 5 hours and will usually be less than 2 hours. Preferably the timeis not more than 60 minutes. As in the case of the1.2.3.4-tetrahydronaphthalene disproportionation reaction, as theisomerization temperature increases the necessary reaction timedecreases. Conversely as the time increases the temperature decreases.Stated in another manner, as either temperature or time increases theamount of by-products increases and this can be offset by adjusting theother variable.

In isomerizing OHA to OHP the BF :OHA mole ratio should be about 07:1and the HFzOHA mole ratio should be about 10:1. The isomerizationtemperature should be about 30 C. and the isomerization time should beas described for the isomerization of OHP to OHA.

The isomerizate normally contains OHA, OHP and a small amount ofby-products formed during the isomerization. The by-products are mainlytrans-syn-transperhydroanthracene and dodecahydrotriphenylene. The OHAand OHP can be separated from the by-products and from each other by thetechniques described in conjunction with the1,2,3,4-tetrahydronaphthalene disproportionation. For example the OHAand OHP can be separated from the by-products by a vacuum distillationand then from each other by fractional crystallization.

The following example illustrates this embodiment of the invention morespecifically.

Example XVI This example is a series of runs in which OHP is isomerizedto OHA at 30 C. and with an isomerization time of 60 minutes. The HFzOHPmole ratio and the BF zOHP mole ratio are varied and are as set out inTable XVI below which. also contains the results of each run. The resultof each run is expressed as the OHAzOHP ratio. It is of course desiredto achieve as high an OI-IAzOHP ratio as possible. The conversion listedis the percentage of the OHP which is converted to any other product.

In each run the OHP, usually about 0.1 mole, is charged to the reactorused in the previous examples and which is maintained at 30 C. except inRun 442650 in which the temperature is 20 C. The HF and BF are thenadded after which the reactor is shaken or stirred for the 60 minutesspecified. At the end of 60 minutes the reactor is opened and thecontents thereof quenched in water. The OHA and OHP are then isolated bythe means described in conjunction with the1,2,3,4-tetrahydronaphthalene disproportionation reaction.

TABLE XVI Run No HFzOHP BF HOHP OHA:OHP Conversion,

0 ratio ratio ratio percent By plotting the OHAzOHP ratio first versusthe HFzOHP ratio and then versus the BF :OHP ratio it is apparent 21that the isomerization is not very eifective unless the amounts of HFand BF are maintained within the previously specified ranges. It is alsoevident that a temperature of 20 C. gives better results (at 90 minutes)than 30 C.

It is also apparent from the data contained in Table XVI that extremelyhigh OHA:OHP ratios are obtainable using the HF-BF catalyst system. Thusratios as high as 8:1 are easily obtainable and ratios as high as 10:1or 1215:1 can be achieved without undue difficulty. Moreover, thedatashow that ratios even as high as 30:1 are also obtainable. It shouldbe noted that it has not heretofore been possible to isomerize OHP toOHA as eifectively as can be done with the HF-BF catalyst. For examplethe isomerization of OHP to OHA with AlCl has been described inSchroeter, Ber. 57B, 1990-2003 (1924) and British Patent 694,961. In theformer reference only about 50% of the OHP charge was isomerized to OHAyielding an OHA:OHP ratio of only 1:1. In the aforesaid British patentabout 84% of the charge was converted to products containing 70% OHA and13% by-products yielding an OHA:OHP ratio of approximately 4.3:1. WithHF:BF OHA:OHP ratios 300400% better than those obtainable with AlCl canbe achieved. Furthermore, the results shown in Table XVI are for anisomerization time of 60 minutes. This is considerably shorter than the15 hours specified in the aforesaid Schroeter reference and the 10-24hours recommended in the aforesaid British patent.

It was mentioned earlier that the HF-BF or HF-BCl catalyst is vastlysuperior to AlCl for converting 1,2,11,4- tetrahydronaphthalene to OHAand OHP. This superiority exists in a number of aspects all of whichwould be highly important in a commercial operation. The followingdiscussion describes these aspects more specifically, in whichdiscussion my catalyst systems will, as in all the previousdescriptions, be referred to as HF-BF (1) It has been shown previouslyherein that OHA- OHP yields based on the total weight of1,2,3,4-tetrahydronaphthalene charge of 75-95% are obtainable withoutdifficulty with HF-BF On the other hand with an AlCl catalyst themaximum yield is about -35%. This is shown more clearly bythe datacontained in Table XVII which presents the results of several runs madeanalogously to the HF-BF catalyzed 1,2,3,4-tetrahydronaphthalenedisproportionation runs described supra except that the catalyst is AlClThe reaction conditions are as specified in the table.

Efforts were made to improve the yield with AlCl by varying reactiontime and temperature, amount of AlCl and by carrying out thedisproportionation in an atmosphere of HCl. This latter technique is awell-known method for improving the catalytic efficiency of AlCl TableXVIII below shows the results of runs made at 65 C., at 1 atmosphereHCl, and at other conditions as specified.

TABLE XVIII 1,2,3,4-tetrahy- Yield, Percent Reaction dronaphthaleneTime, Min. Conversion,

Percent OHA-OHP PTB 0.5 Mole Percent: H01

5.0 Mole Percent A101 10 Mole Percent A101 Table XIX shows the resultsof a number of runs made at 5 mole percent AlCl 1 atmosphere HCl, andvarying reaction temperatures and times.

TABLE XIX 1,2,3,4-tetrahy- Yield, Percent Reaction dronaphthalene Time,Min. Conversion,

Percent OHA-OHP PTB Temp.=45 C.

Temp.=65 O.

Temp.=85 O.

Examination of the data in Tables XVII-XIX shows that the maximum yieldobtainable with A101 is about 30%, distinctly less than can be achievedwith HFBF Carrying out the AlCl catalyzed disproportionation in thepresence of hydrogen (another known technique for improving thecatalytic efiiciency of AlCl in the presence of higher HCl pressures, orin the presence of both H and HCl does not result in significantlydifferent yields. This is apparent from Table XX which shows the results23 of AlCl runs at a 60 minute reaction time and other conditions asstated.

viously presented. For example Table XVII shows that a yield of 25.7%OHAOHP can be achieved with AlCl (2) A second disadvantage of the AlClprocess is that it produces the particularly undesirable by-productdiphenylbutane. This by-product is not produced in the HF-BF process orif it is produced it is converted to other products such as1,2,3,4-tetrahydronaphthalene or benzene. In any event in the AlCl runsdescribed herein diphenylbutane was detected in significant amounts bychromatographic analysis of the reaction product mixtures. Conversely,the same analysis of HF-BF runs described herein is negative, i.e., thisby-product is not present in the reaction product mixture.

Diphenylbutane is particularly undesirable because its physicalproperties, particularly its boiling point, are very similar to those ofOHP hence it is very difficult to separate from OHP. This means not onlythat pure OHP is diflicult to isolate but also that if OHP is to berecycled to the disproportionation vessel for isomerization to OHA thediphenylbutane will accumulate in the system. Such an accumulation willeventually shut down the process unless a purge stream is taken but apurge stream also involves the loss of the desirable OHP. All theseproblems are avoided with an I-IF-BF catalyst.

(3) A third disadvantage of the A101 process is that it is not nearly asselective as the HF-BF process. It has been shown hereinbefore that withHF-BE, either OHA- OHP or PTB can be made to the essentially completeexclusion of the other. An examination of the data contained in TablesXVII-XX shows, for example, that the highest ratio of OHAOHP to PTB isabout 1. On the other hand the HFBF data presented supra shows that aninfinitely high (zero PTB) OHAOHPzPTB ratio is readily obtainable andthat ratios of about 40:1 to about 80:1 are almost always obtained. Thisselectivity is an important factor because in a commercial operation itwill usually be desirable to either make only one product or at leastonly one product at a time.

(4) A fourth disadvantage of the AlCl process is the nature of theby-products formed. Both AlCl and HF-BF form some by-products which havenot been listed in the tables herein because all of them have not beencompletely identified. However, they are part of the reaction productmixture. As previously described one method of working up the reactionproduct mixture involves quenching it in water, adding pentane as asolvent or diluent for the reaction products, decanting the pentanesolution, and recovering the desired products from the latter solution.The use of the pentane improves the separation of the organic phase fromthe aqueous phase. In the HF-BF process the organic products dissolve inpentane without difficulty, i.e., in 1-2 minutes, whereas with AlCldissolution takes much longer. Whatever the reason therefor, thisditference in solution rate would be an important factor in a commercialoperation.

(5 A fifth disadvantage of the AlCl process is that the reaction time ismuch longer than is required with HF- BF In other words, less time isrequired with HF-BF to make the same or higher yield of product than isrequired with AlCl This is clearly shown by the data pre in one hourwhereas Table IV shows that an OHA-OHP yield of 55.5% is obtained in 15minutes. Stated in another manner a 100% higher yield is achieved withHF-BF in only 25% of the time.

(6) Another disadvantage of the AlCl process arises out of the nature ofthe high boiling by-products made in that process. By high boilingby-products is meant the reaction products boiling above OHA and OHP.The disadvantage is that the high boiling by-products from the HI -B1process can be readily converted to OHAOHP by further treatment withHFBF whereas those in the AlCl process are not readily converted toOHA-OHP by further treatment with AlCl The high boiling byproducts fromthe AlCl process normally contain about 60% PTB, some diphenylbutane,and some other materials not readily identifiable. The high boilingby-products from the HFBF process contain little or no PTB (assumingOHA-OHP is the desired product) with the balance being other compoundsall of which have not been completely identified. The difference in thefacility with which the high boiling by-products from each process canbe converted to OHA-OHP is illustrated in the following examples. Someexample numbers have been skipped in order to maintain correspondencebetween example numbers and table numbers.

Example XXI This example is a series of two runs in which the startingmaterial is a high boiling fraction distilled from the reaction productmixture of one of the AlCl runs described supra. The high boilingfraction is everything distillable boiling above OHA and OHP. Theefficiency of the distillation equipment is such that the distillateactually contains 90.5% (by weight) high boiling fraction and 9 /2%OHAOHP. The high boiling fraction contains 61% PTB and the 9 /2% OHAOHPalso includes some diphenylbutane. In one run 100 parts of thisdistillate, i.e. 90.5 parts high boiling fraction and 9.5 parts OHAOHPis contacted with 2 mole percent AlCl at C. for one hour. The amount ofAlCl is based on the amount of high boiling fraction and the molecularWeight of the latter is assumed to be 300. The reaction product mixtureis then analyzed and is found to contain on a benzenefree basis 14.6%1,2,3,4-tetrahydronaphthalene, 10.9% OHAOHP (including diphenylbutane)with the balance being high boiling fraction. The other run is identicalexceptthat 5 mole percent AlCl is used. In this case the reactionproduct mixture analyzes 56.1% 1,2,3,4-tetrahydronaphthalene, 12.5%OHAOHP (including diphenylbutane), the balance being high boilingmaterial, i.e., products boiling above OHA and OHP. When it isconsidered that the starting material contains 9%% OHAOHP the resultsshow that very little OHA-OHP is produced. In the second run asubstantial amount of 1,2,3,4-tetrahydronaphthalene is produced andalthough this is a more desirable material than the high boilingmaterial it is not of course as desirable as OHA and OHP.

Example XXII This example is a run in which the starting material is ahigh boiling fraction distilled from the reaction product mixture of oneof the HF-BF runs described supra. The high boiling fraction analyzes93.4% high boiling material and 6.6% OHA-OHP. The high boiling fractioncontains a negligible amount of PTB. This high boiling fraction iscontacted at 50 C. for one hour with HF and BF the amount of HF being9.4 moles per mole of high boiling fraction and the amount of BF being0.67 moles per mole of high boiling fraction. As in the previous examplean average molecular weight of 300 is used for calculation of moleratios. It will be noted that the 50 C. temperature in this example isabout the optimum temperature for the HF-BF process for making OHA-OHPand that the 90 C. temperature used in the prior example is about theoptimum temperature for making OHA-OHP in the AlCl process. The reactionproduct mixture is analyzed as in the previous example and is found tocontain 7.8% 1,2,3,4-tetrahydronaphthalene, 56.7% OHA-OHP and 35.4% highboiling material. Even when allowance is made for the 6.4% OHA-OHP inthe starting material these results show that a very substantialquantity of the high boiling fraction is converted to OHA-OHP.

The advantage resulting from being able to convert a substantial portionof' the high boiling fraction to OHA- OHP is readily apparent. It meansthat the high boiling fraction can be recycled to the disproportionationvessel and the ultimate yield of OHA-OHP thereby increased. In the AlClprocess the high boiling fraction would have to be either discarded orsome new use found for it.

(7) A further advantage of the HFBF catalyzed disproportionation processover the AlCl process is that in the former the catalyst can berecovered and reused without deactivation thereof. A convenient methodof effecting such recovery has been described hereinbefore, i.e., at theend of the disproportionation the HF and the BF are distilled from thereaction vessel. They can then be reused to catalyze thedisproportionationof additional 1,2,3,4- tetrahydronaphthalene and itwill be found that the yield of OHAOHP in the subsequentdisproportionation is essentially the same as in the firstdisproportionation. This is shown by two runs in each of which1,2,3,4-tetrahydronaphthalene is disproportionated at 50 C. for 90minutes with an HF:1,2,3,4-tetrahydronaphthalene ratio of 10:1 (20.0grns. HF) and a BF :1,2,3,4-tetrahydronaphthalene ratio of 0.6:1 (4.1grns. BF In the first run fresh HF and BF are used and in the second runthe HF and BF are obtained by distilling same from the reaction productmixture at the end of the first run. The total amount recovered by suchdistillation is 24.2 grns. The yield of OHA- OHP in the second run isexactly 1.0% higher than in the first run which clearly shows that nodeactivation of the HF-BF catalyst occurs.

If AlC1 is used as the catalyst it gradually deactivates and musteventually be replaced. If AlCl per se is used the only practical meansof recovering the catalyst is to quench the reaction product mixture indilute HCl. This results in a dilute HCl solution of hydrated AlCl andan organic phase immiscible therewith which contains the variousreaction products. This technique completely deactivates the AlClbecause hydrated AlCl has no catalytic activity. If instead of usingAlCl per se the AlCl is used in the form of a liquid complex with HCland a compound such as 1,2,3,4-tetrahydronaphthalene then the catalystsystem remains as a separate phase throughout the disproportionation andcan be readily decanted from the organic phase containing the variousreaction products. This procedure, described in detail in the copendingapplication of A. Schneider, Ser. No. 401,663, filed Oct. 5, 1964,permits ready recovery and reuse of the catalyst. Unfortunately 26however, the catalyst phase is gradually deactivated so that it musteventually be discarded and replaced. In other words, the AlCl complexyields more OHA-OHP per gram of AlCl than can be obtained with AlCl perse but the amount of OHA-OHP decreases in each subsequentdisproportionation which means that the catalyst is gradually becomingdeactivated. As described above with HF BF no such deactivation occurs.

The invention claimed is:

1. Method which comprises (1) contacting with liquid HF and borontrihalide a starting material characterized in that it is a polycyclicaromatic containing a condensed ring group having an unsubstitutedaromatic ring with exactly two condensed carbon atoms and anunsubstituted saturated ring with exactly two condensed carbon atoms,the amounts of HF and boron trihalide being at least 5 moles per mole ofsaid starting material and at least 0.5 mole per mole of said startingmaterial respectively, said contacting being for a time sufficient toeffect self-reaction of said starting material and (2) recovering fromthe reaction product mixture a compound selected from the groupconsisting of diaryl alkanes and polycyclic aromatic compoundscontaining one more unsubstituted saturated ring having exactly twocondensed carbon atoms than said starting material, said trihalide beingER; or BCI 2. Method which comprises contacting1,2,3,4-tetrahydronaphthalene with (1) at least 5 moles liquid HF permole of 1,2,3,4-tetrahydronaphthalene and (2) at least 0.5 mole BF orBCl per mole of 1,2,3,4-tetrahydronaphthalene at a temperature in therange of -100 to 130 C. for a time sufficient to efiFect self-reactionof said 1,2,3,4-tetrahydronaphthalene, and recovering from the reactionproduct mixture a compound selected from the group consisting ofoctahydroanthracene, octahydrophenanthrene, and phenyltetralylbutane.

3. Method according to claim 2 wherein said temperature is in the rangeof 15 to 130 C. and the compound recovered is selected from the groupconsisting of octahydroanthracene and octahydrophenanthrene.

4. Method according to claim 3 wherein said temperature is in the rangeof 40 to C.

5. Method according to claim 3 wherein octahydroanthracene andoctahydrophenanthrene are recovered from the reaction product mixture ina yield of over 75%.

6. Method according to claim 3 wherein both octahydroanthracene andoctahydrophenanthrene are recovered and the octahydrophenanthrene isthereafter catalytically isomerized with HF and BF or HF and BCl tooctahydroanthracene.

7. Method according to claim 6 wherein the ratio of octahydroanthraceneto octahydrophenanthrene in the isomerizate is at least 10 to 1.

8. Method according to claim 3 wherein said time is in the range of 1minute to 2 hours.

9. Method according to claim 3 wherein the reaction product mixture isessentially free of phenyltetralylbutane.

10. Method according to claim 3 wherein the boron compound is BF 11.Method according to claim 2 wherein the amount of liquid HF is at least7 moles per mole of 1,2,3,4-tetrahydronaphthalene and the amount of BFor BCl is at least 0.6 mole per mole of 1,2,3,4-tetrahydronaphthalene.

12. Method according to claim 2 wherein said temperature is in the rangeof to 15 C. and the compound recovered is phenyltetralylbutane.

13. Method according to claim 12 wherein said temperature is in therange of 60 to 10 C.

14. Method according to claim 12 wherein the reaction product mixture isessentially free of octahydroanthracene and octahydrophenanthrene.

15. Method according to claim 12 wherein said time is in the range of0.5 minute to 1 hour.

16. Method according to claim 12 wherein the amount of liquid HF is atleast 7 moles per mole of 1,2,3,4-tetrahydronaphthalene and the amountof BF or BCl is at least 0.6 mole per mole of1,2,3,4-tetrahydronaphthalene.

17. Method which comprises contacting 1,2,3,4-tetrahydronaphthalene with(1) at least 5 moles liquid HF per mole of 1,2,3,4-tetrahydronaphthaleneand (2) at least 0.5 mole boron trihalide per mole ofl,2,3,4-tetrahydronaphthalene at a temperature in the range of 15 to 130C. for a time suflicient to effect disproportionation of saidl,2,3,4-tetrahydronaphtha1ene to octahydroanthracene andoctahydrophenanthrene, said boron trihalide being BF or BCl bringing thetemperature, the amount of HF, and the amount of BF or BCl in thereaction product mixture to 3060 C., .1-2 moles HF per mole of saidoctahydroanthracene, .05-1 mole boron trihalide per mole of saidoctahydroanthracene, respectively, thereby to effect isomerization ofthe octahydrophenanthrene therein to octahydroanthracene, the ratio ofthe octahydroanthracene resulting from said isomerization to theremaining octahydrophenanthrene being at least 10 to l, and recoveringoctahydroanthracene from the resulting isomerizate.

18. Method which comprises contacting indan with (1) at least 5 molesliquid HF per mole of indan and (2) at least 0.5 mole BF or BCl per moleof indan at a temperature in the range of 20 to 120 C. for a timesufficient to effect self-reaction of said indan, and recovering fromthe reaction product mixture a compound selected from the groupconsisting of as-hydrindacene and phenylindanylpropane.

19. Method according to claim 18 wherein said temperature is in therange of 40 to 120 C. and the compound recovered is as-hydrindacene.

20. Method according to claim 19 wherein said temperature is in therange of 50 to 100 C.

21. Method according to claim 19 wherein said time is in the range of 1minute to 5 hours.

22. Method according to claim 19 wherein the ratio of as-hydrindacene tophenylindanylpropane in the reaction product mixture is at least 4 to 1.

23. Method according to claim 18 wherein the amount of liquid HF is atleast 7 moles per mole of indan and the amount of BF or B013 is at least0.6 mole per mole of indan.

24. Method according to claim 18 wherein said temperature is in therange of 20 to 80 C. and the product recovered is phenylindanylpropane.

25. Method according to claim 24 wherein said temperature is in therange of to 60 C. V

26. Method according to claim 24 wherein said time is in the range of .5minute to 1 hour.

27. Method according to claim 18 wherein the boron compound is BF 28.Method according to claim 24 wherein the who of phenylindanylpropane toas-hydrindacene in the reaction product mixture is at least 4 to 1.

29. 1-(4-as-hydrindacene)-3-phenylpropane.

30. Method of preparing 1-(4-as-hydrindacene)-3- phenylpropane whichcomprises contacting indan with (1) at least 5 moles liquid HF per moleof indan and (2) at least 0.5 mole BF or BCl per mole of indan at atemperature in the range of 20 to 150 C. for a time of at least oneminute and recovering 1-(4as-hydrindacene)-3- phenylpropane from thereaction product mixture.

31. Method according to claim 30 wherein the amount of liquid HP is atleast 7 moles per mole of indan and the amount of BF or BCl is at least0.6 mole per mole of indan.

32. Method according to claim 30 wherein the temperature is in the rangeof 40 to 120 C.

33. Method according to claim 30 wherein said time is in the range of 5minutes to 3 hours.

34. Method according to claim 30 wherein the boron compound is BF 35.Method which comprises contacting phenyltetralylbutane with (:1) atleast 1 mole liquid HF per mole of phenyltetralylbutane and (2) at least0.1 mole BF or BCl per mole of phenyltetralylbutane at a temperature inthe range of 15 to 130 C. for a time sufficient to effect reaction ofsaid phenyltetralyl-butane, and recovering from the reaction productmixture a compound selected from the group consisting ofoctahydroanthracene and octahydrophenanthrene.

36. Method according to claim 35 wherein the amount of HP is at least 5moles and the amount of BF or BCl is at least 0.5 mole, each being permole of phenyltetralylbutane.

37. Method according to claim 35 wherein the temperature is in the rangeof 30 to C.

38. Method according to claim 35 wherein the time is in the range of 2minutes to 3 hours.

39. Method according to claim 35 wherein the boron compound is BF 40.Method which comprises contacting phenylindanylpropane with (1) at least1 mole liquid HF per mole of phenylindanylpropane and (2) at least 0.1mole BF or BCl per mole of phenylindanylpropane at a temperature in therange of 40 to C. for a time sufiicient to effect reaction of saidphenylindanylpropane, and recovering from the reaction product mixtureas-hydrindacene.

41. Method according to claim 40 wherein the amount of HF is at least 5moles and the amount of BF or BCl is at least 0.5 mole, each being permole of phenylindanylpropane.

42. Method according to claim 40 wherein the temperature is in the rangeof 50 to 100 C.

43. Method according to claim 40 wherein the time is in the range of 2minutes to 3 hours.

44. Method according to claim 40 wherein the boron compound is BF 45.Method which comprises contacting octahydrophenanthrene with (l) 0.1-2.0moles liquid HF per mole of octahydrophenanthrene and (2) .05-1 mole BFor BCl per mole of octahydrophenanthrene at a temperature of 30 to 60 C.for a time sufiicient to eifect isomerization of saidoctahydrophenanthrene to octahydroanthracene and recovering saidoctahydroanthracene.

46. Method according to claim 45 wherein the ratio ofoctahydroanthracene to octahydrophenanthrene in the isomerizate is atleast 10 to 1.

47. Method according to claim 45 wherein said temperature is 0 to 50 C.

48. Method according to claim 45 wherein said time is 5 minutes to 60minutes.

49. Method according to claim 45 wherein the boron compound is BF 50.Method according to claim 45 wherein the amount of HF is 0.25 to 1.5moles and the amount of BF or BCl is 0.2 to 0.8 mole, each being permole of octahydrophenanthrene.

51. Method according to claim 45 wherein the amount of HF is 0.4 to 1.2moles and the amount of BF or BCl is about 0.6 mole, each being per moleof octahydrophenanthrene.

52. Method according to claim 45 wherein said temperature is about 15 toabout 30 C.

53. Method which comprises contacting octahydroanthracene with (1) about10 moles liquid HF and (2) about 0.7 moles BF or BCl each being per moleof octahydroanthracene, at a temperature of about 30 C. for a timesuflicient to effect isomerization of said octahydroanthrecene tooctahydrophenanthrene, and recovering said octahydrophenanthrene.

(References on following page) 29 30 References Cited FOREIGN PATENTSUNITED STATES PATENTS 694,961 7/1953 Great Britain.

12,884,469 4/1959 McCaulay 260-67 1 X 3,197,513 7/1965 Chapman et a1.260-66 8 DELBERT GANTZ Emmme" 3,244,753 4/1966 Eberhardt 260-668 5 c. R.DAVIS, Assistant Examiner.

1. METHOD WHICH COMPRISES (1) CONTACTING WITH LIQUID HF AND BORONTRIHALIDE A STARTING MATERIAL CHARACTERIZED IN THAT IT IS A POLYCYCLICAROMATIC CONTAINING A CONDENSED RING GROUP HAVING AN UNSUBSTITUTEDAROMATIC RING WITH EXACTLY TWO CONDENSED CARBON ATOMS AND ANUNSUBSTITUTED SATUREATED RING WITH EXACTLY TWO CONDENSED CARBON ATOMSTHE AMOUNT OF HF AND BORON TRIHALIDE BEING AT LEAST 5 MOLES PER MOLE OFSAID STARTING MATERIAL AND AT LEAST 0.5 MOLE PER MOLE OF SAID STARTINGMATERIAL RESPECTIVELY, SAID CONTACTING BEING FOR A TIME SUFFICIENT TOEFFECT SELF-REACTION OF SAID STARTING MATERIAL AND (2) RECOVERING FROMTHE REACTION PRODUCT MIXTURE A COMPOUND SELECTED FROM THE GROUPCONSISTING OF DIARYL ALKANES AND POLYCYCLIC AROMATIC COMPOUNDSCONTAINING ONE MORE UNSUBSTITUTED SATURATED RING HAVING EXACTLY TWOCONDENSED CARBON ATOMS THAN SAID STARTING MATERIAL, SAID TRIHALIDE BEINGBF3 OR BCL3.